Circuit breaker



July 18, 1933.

T. E. MURRAY CIRC Filed UIT BREAKER Oct. 5, 1928 5 Sheets-Sheet lTIzOmm'EMU/Tay @MA/ em T. E. MURRAY CIRCUIT BREAKER July 18, 1933.

Filed Oct. 5, 1928 5 Sheets-Sheet 2 womtoz Iwmas'EnMl/Ilay T. E. MURRAYCIRCUIT BREAKER July 18, 1933.

Filed Oct. 5, 1928 5 Sheets-Sheet 3 I'ig. 4

Tilo

T. E. MURRAY CIRCUIT BREAKER July 18, 1933.

Filed Oct. 5, 1928 5 Sheets-Sheet 4 wvmfttoz IbOmaS'MI/rray July 18,1933.

CIRCUIT BREAKER Filed Oct. 5, 1928 5 Sheets-Sheet 5 i 50 terminals 7 ofthe line conductors.

. arlallgemel'l 4 `throu gh Patented 'July 18, 1933 UNITED STATES PATENToFFlcE THOMAS E. MURRAY, or BROOKLYN,

NEW YORK; JOSEPH BRADLEY MURRAY, THOMAS E. MURRAY, JR., AND JOHN F.MURRAY, EXECUTORS 0F SAT1) THOMAS E. MURRAY. DECEASED, ASSIGNORS TMETROPOLITAN DEVICE CORPORATION, A CORPORATION OF NEW 'YORK Application:tiled Octoberl En', 1928. Serial No. 310,507.

In my prior Patent #1,833,173 issued Nov. 24, 1931, on an applicationliled July 10, 1928, and my application No. 296,881, filed Au 2, 1928, lhave described circuit brea ing apparatus including switches and Jfusesfor breaking the circuit particularly in lines carrying high voltages.rlhe present inventionprovides improvements designed for extinguishingarcs formed in the separation of the contacts or in the blowing of thefuses of such circuit breakers and of other apparatus of the samecharacter.

The accompanying drawings illustrate embodiments of the invention.

Fig. 1 is a longitudinal vertical section ot a circuit breaker without afuse, partly in elevation; 4

Fig. 2 is a cross-section on the line 2-2 oiz Fig: 1;

ig. 3 is a section similar to Fig. 1, showingvthe parts in a diii'erentposition;

1 in t e improvement applied with a fuse; ig. `5 is a similar view of amodification; -rFig. 6 is a perspective view of a group to fuses;

Fig. 7 is a vertical section illustrating a different type of fuse;

Fig. 8 is a section showing a combination of the arrangements of Figs. 1and 4.

Referring to Figs. 1 and 2, the mechanism is carried in a box or casinghaving end walls l, side walls 2, a bottom 8 and a cover which is acentral opening hereinafter referred to. The conductors 5 and 6 passthrough the end Walls and are mounted on the bottom with upwardlyextending switch blades 7. A conducting bridge 8 has end terminals 9adapted to enter between the blades 7 or to be lifted ont of contactwith the latter. The bridge 8 is mounted on a transverse slide 10 whichextends down through the bottom of the box and has an upward portion 11with flanges 12 which serve to close the central opening in the cover,above which is a handle 13. 'lhe carrier`thus forms an insulatingartitionor barrier entirely across the box between the separatedterminals.

. 4 is a section similar to Fig. 1 show# l/Vhen the carrier is raised tobrealr the circuit, sliding barriers 14 are arranged to move across thegap between the terminals 7 and 9 so as to prevent the establishment ormaintenance of a conductive'arc between the These slides are held attheir side ed es in guides 15 (Fig. 2) on the side walls 0% the box.They are pressed forward by springs 16 engaging lugs 17 on their undersides.

lhe carrier 10 has a pair of cam projections 18 engaging projections 19on top oi' the slides and holding the slides back until the carrier israised sufficiently to pass the cams 18 above the projections 19; where-6 upon the slides will spring into the gap. When the carrier is loweredthe cams 18 engage the tops of the projections 19 and force the slidesback to permit the entry of the ends 9 of the conductive bridge into theswitch blades 7.

Within the two legs of the conductive bridge there is also an upwardtransverse projection 20 through the ycentre of which the carrier 10slides. Thi projection 20 is xed on the bottom 3 of he box and has airpassages 2]:y through it leading from..

openings in the bottom of the box to lateral openings just at the topofthe switch blades 7. 'lhese passages are for blastsof air which are tobe applied at the proper moment to blow out any arc which tends to ilormbetween the switch terminals as they are separated.

rlhe sliding barriers 14 carry which extend through the end walls 1 tolpoints outside of the box so as to remove the hot air and the conductivevapor from the proximity of the parts within. When the slides 14 moveinward as in Fig. 3, the end of the tube bears against the .partition20. The barrier 14 is just short of the back of the passage 21. The endof the sliding barrier is also specially shaped, being notched toco-operate with specially shaped tubes 22.

ILO

The breaker may be actuated by hand or by various mechanisms. Fig. 1illustrates a distant control mechanism, using solenoids. The lowerendof the carrier constitutes an. extension 23 whichV carries a lug 24adapted when raised to be caught by the spring latch 25. A solenoid 26serves to withdraw the latch and drop the carrier to circuit closingposition. -4

Attached to the link 27 is a' link 34, the lower end of which is slottedand engaged by a pin on the upper end of the core 33 of a solenoid' 32which when energized pulls the core downward. The forward end of thelink 27 is bevelled and when it swings downward, catches under a rolleron the end of arm 34, the lower end of which is pivoted to a fixedsupport and the intermediate portion of which is connected to a core ofsolenoid 35 which when energized pulls the core and releases the latch.

Nowv when it is desired to open the switch, the solenoid 35 isenergized; when this .hap-

' pens solenoid 35 pulls the core and releases the latch and a coil'spring then throws the end of the link 27 upward to such a distance thatthe projection 24 snaps past the spring latch 25 which holds the switchopen. Current is then applied to energize solenoid 32 and core 33 pullsthe link 27 to the position of Fig. 1 so that the parts are ready forthe closing of the switch. The closing of the switch is accomplished byreleasing latch 25 by means of solenoid 26 disengaging the projection 24which allows carrier 23 to drop to the position shown in Fig. 1, therebyclosing the contacts.

reservoir of air under pressure leads through a pipe 36 and a valve 37to a rubber or other' flexiblev hose connection 38 which-leads to thelower ends of the passage 21 within the box.

The valve 37 has an operating arm 39 connected by a link 40 to thelifting link 27. When the carrier is lifted, therefore, the air g valveis simultaneously opened and air under being applied to the fuse.

pressure is blown through the passages 21 across the space between theseparated term,- inals and through the tubes 22 to the outside of thebox.

A switch or circuit breaker of the same general type, but with theaddition of a fuse, is illustrated in Fig. 4, the air blast, however, Inthat case the switch illustrated is intended for usev only after a fusehas blown and is to be replaced; but where the switch and the fuse areboth intended to be used in the breaking of the circuit, an air' blastmay be applied to each of them. It is assumed that the structure of Fig.4 is in a casing similar to that of Fig. 1.

The leads 5 and 6 with upright switch blades 7 are arranged on oppositesides of `a stationary block or partition 4l. The carrier 42 forms aninsulating partition extend;

ing across the box, and the movable switch blades 9 are bridged at theirupper ends by lfar apart as their length and the enclosing casing willpermit.

For blowing out the arc which tends ,to form, the carrier 42 has apassage 47 within it leading to a hole in the casing 45 of the fusewhich may be covered by an easily breakable piece of paper 48. The lowerend of the carrier is connected to a flexible air hose 49 which leadsair under compression to the passage 47. The air pressure may be appliedconstantly, or by an automatic valve as in Fig. 1.

The arrangement of Fig. 4 is specially designed for such uses as aredescribed in the application of Thomas E. Murray, J r., No. 257,861filed February 29, 1928 in which the opening of a switch on the mainline throws the current on to a parallel line containing the fuse, whichthen blows and breaks the circuit, thus permitting the use of acomparatively simple main switch on higlrtension lines. When such a fuseblows, the carrier will be lifted, disconnecting the cables at theterminals 7 and 9, and a new fuse will be inserted. y

In the alternative form shown in Fig. 5, the carrier 42 terminateswithin the block 41 and the air pipe 49 is mounted directly in thepassage 50 in which thesliding carrier is guided within the block 41.This construction permits the complete removal of the carrier 42 withoutdetaching the air pipe.

For certain cases a multiplicity of fuses, either in parallel or inseries, are mounted on a carrier such as 51, Fig. 6. The passage 52therein communicates with all of the three fuses shown. Otherwise theconstruction may be as in either Fig. 4 or Fig. 5.

According to Fig. 7 the main part of the carrier 42 is similar to thatof Figs. 4 rand 5, with a passagev 47 therein for the air. The fuse,however, is somewhat different. The cables 43 at` their u per ends arefastened by clamps 53 to a ilse strip 54 which has its breaking point atthe center and overlies the end of the passage 47. rlhe carrier itselfis shaped to form a flaring transverse passage 55 between the lower partof the carrier and the flange 56 which forms part of the cover of thebox. The fuse, therefore, is practically unenclosed. When the fuse blowsthere will be a repulsive force Attached to the g between the twobranches of the cable 43 which will tend to throw them apart. This maybe assisted by springs or by weights 57 at the ends of cords 58 whichare attached to the clamps 53 and pass over guide pulleys 59. lAnytendency to form an arc between the burnt ends of the fuse or the endsof the cables 'will be overcome by the blast of air which enters throughthe passage 47 and blows violently in both directions through thepassage 55. Y

Fig. 8 illustrates the application of the improvement to both the switchblades .and the fuse. The carrier 42 with the fuse in its upper portion`is similar to that of Fig. 4. The switch blades 7- and 9 overlie theends of passages 21 in the block 2O which carry blasts of air which aredischarged through the tubes 22 as in Fig. l. The air hose 49 and 38carry the air to the passages 47 and 21 respectively.

Various modifications in detail and in the arrangement of the partsmaybe made by those skilled in the art without departing from theinvention as defined in the following claims.

I claim:

l. A circuit breaker comprising a casing,

a fixed contact in said casing, a contact mov-j able into and out ofcontact with said fixed contact, means for blowing a blast of airbetween said fixed and said .movable contacts upon the separation ofsaid contacts, and a barrier movable between said contacts upon theirseparation and having means to enclose said blast of air and conduct itoutside of said casing.

2. A circuit breaker' which comprises a pair of fixed contacts, abarrier between said contacts, said barrier having air passages withdischarge outlets directed across the edges of said contacts, a slideslidable in said barrier, a'contact on said slide to contact with landseparate from said fixed contacts, and means actuated by the separationof said contacts to admit air to said passages.

3. A circuit breaker which comprises a casing, a pair of fixed contactsin said casing, a barrier between said contacts, said barrier having airpassages with discharge outlets f directed across the edges of saidcontacts, a slide slidable in said barrier, a contact on said slide tocontact with and separate from said fixed contacts, means actuated bythe separation of said contacts to admit air to said passages, and meansmovable towards said barrier to enclose saidblast of air and conduct itoutside said casing.

4. A circuit breaker which comprises a casing, a pair of fixed contactsin said casing, a barrier between said contacts, said barrier having airpassages with discharge outlets directed across the edges of saidcontacts, 'a slide slidable in said barrier, a contact on said slide tocontact with and separate from v.

said @fixed contacts, means actuated by the separation of said contactsto admita blast oi? air to said passages, means movable towards saidbarrier to enclose said blast of air, and a fuse on said slide connectedto said movable contact, and an air passage in said slide and closed bysaid fuse.

5. A circuit breaker which comprises a casing, a pair of fixed contactsin said casing,

a barrier between said contacts, said barrier having air passages withdischarge outlets directed across the edges of said contacts, a slideslidable in said barrier, a contact on said slide to contact with andseparate from said fixed contacts, means actuated by the separation ofsaid contacts to admit a blast of air to said passages, means movabletowards said barrier to enclose said blast of air, a fuse on said slideconnected to said movable contact, and an air passage in said slide andclosed by said fuse, the air passage in said slide communicating withthe air passages in said barrier.

leo

